Effect of silicate solubilizing bacteria and fly ash on silicon uptake and yield of rice under lowland ecosystem

A field experiment was conducted in sandy loam soils of eastern farm, Agricultural Engineering College and Research Institute, Kumulur, Tamil Nadu, India to study the effect of silicon on yield and uptake of rice (var. BPT 5204) during Kharif season of 2010-11 by taking the treatment combinations based on graded levels of Fly Ash (FA), Silicate Solubilizing Bacteria (SSB) and Farm Yard Manure (FYM) at fixed fertilizer schedule. The experimental soil (0-15 cm) had pH 7.22; organic C 1.4 %; available Si 66.0 mg kg-1; available N 266.0 kgha-1; available P 14.42 kgha-1 and available K 107.50 kgha-1. The results of graded levels of FA show that all the growth and yield attributes were significantly influenced by silicon uptake. The mean silicon uptake at panicle initiation, straw and grain at harvest varied from 53.8 - 98.7, 105.5 - 197.2 and 21.4- 62.3 kgha-1 respectively, in rice. Number of filled grains per panicle and grain yield displayed conspicuous relationships with content of Si in grains. The highest mean grain yield of 3622 kg ha-1 was recorded by the addition of SSB+FYM followed by FYM (3530 kg ha-1), SSB (3310 kg ha-1) and control (3240 kg ha-1). The combined application of 25 t ha-1 FA with SSB+FYM was recorded the highest grain yield of 3710 kg ha-1 which was 16.3 per cent moreover yield of control. The results further show that 25 t ha-1 FA and SSB+FYM have been proved to be superior treatments for best management of silicon in coastal loamy sand soils under irrigated rice ecosystem